Simplify the following expression: $k = \dfrac{2f^2 - gf}{hf} - \dfrac{5f^2 + 3gf}{hf}$ You can assume $f,g,h \neq 0$.
Since the expressions have the same denominator we simply combine the numerators: $k = \dfrac{2f^2 - gf - (5f^2 + 3gf)}{hf}$ $k = \dfrac{-3f^2 - 4gf}{hf}$ The numerator and denominator have a common factor of $f$, so we can simplify $k = \dfrac{-3f - 4g}{h}$